Generally, a downlight is an illumination system in which a light source is built in a hole perforated through a ceiling. This system is widely used for architectural illumination to provide illumination integrated with a building.
Since such a downlight is recessed in a ceiling, there is little or no exposure of the elements of the downlight. In this regard, there may be an advantage in that the ceiling has a smart appearance. Furthermore, such a downlight may be a system suitable for creation of a relaxed room atmosphere in that the ceiling is dark.
However, such an illumination system may be more suitable for a narrow indoor space than a wide indoor space. Furthermore, this system may require a number of LED light sources.
To this end, it may be necessary to develop an illumination unit suitable for a wide indoor space while employing a reduced number of LED light sources.